package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */
// urlPatterns 指定拦截路径   filterName 指定拦截名称
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    // 路径匹配器， 支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;

        // 1. 获取本次请求的 URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}", requestURI);

        // 定义不需要处理的请求路径
        String[] urls = new String[] {
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/user/sendMsg",    // 移动端发送短信
                "/user/login",       // 移动端登陆
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };

        // 2. 判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        // 3. 如果不需要处理， 则直接放行
        if (check) {
            log.info("本次请求{}不需要处理", requestURI);
            filterChain.doFilter(request, response);
            return ;
        }

        // 4. 后台： 判断登陆状态， 如果已登录，则直接放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录， 用户id为：{}", request.getSession().getAttribute("employee"));

            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            long id = Thread.currentThread().getId();
            log.info("线程id为：{}", id);

            filterChain.doFilter(request, response);
            return ;
        }

        // 4. 移动端：  判断登陆状态， 如果已登录，则直接放行
        if (request.getSession().getAttribute("user") != null) {
            log.info("用户已登录， 用户id为：{}", request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            long id = Thread.currentThread().getId();
            log.info("线程id为：{}", id);

            filterChain.doFilter(request, response);
            return ;
        }

        // 5. 如果未登录则返回未登录结果,通过输出流的方式向客户端页面响应数据
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
//        log.info("拦截到请求：{}", request.getRequestURI());
//        filterChain.doFilter(request, response);
    }

    /**
     * 路径匹配， 检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }

        return false;
    }

}
